Antenna device and communication apparatus

Abstract

According to one embodiment, an antenna device includes a first split ring, a second split ring, and a power supply line. The first split ring is made of a conductor and has a first gap. The second split ring is made of a conductor, is formed in an opening of the first split ring, and has a second gap formed at a position facing the conductor of the first split ring. The power supply line is connected to the first split ring.

What is claimed is: 
     
         1 . An antenna device comprising:
 a first split ring comprising a conductor and having an opening and a first gap;   a second split ring comprising a conductor, formed in the opening of the first split ring, and having a second gap at a position facing the conductor of the first split ring; and   a power supply line connected to the first split ring.   
     
     
         2 . The device according to  claim 1 , further comprising:
 a dielectric plate, wherein   the first split ring and the second split ring are positioned on the dielectric plate.   
     
     
         3 . The device according to  claim 2 , wherein
 the first split ring is positioned on a first surface of the dielectric plate, and   the second split ring is positioned on a second surface facing the first surface.   
     
     
         4 . The device according to  claim 1 , wherein
 the second gap is in a direction opposite to a direction of the first gap.   
     
     
         5 . The device according to  claim 1 , wherein the first split ring has a first capacitance and the second split ring has a second capacitance. 
     
     
         6 . The device according to  claim 5 , wherein the first capacitance is different from the second capacitance. 
     
     
         7 . The device according to  claim 1 , wherein the first split ring has a first inductance and the second split ring has a second inductance. 
     
     
         8 . The device according to  claim 7 , wherein the first inductance is different from the second inductance. 
     
     
         9 . The device according to  claim 1 , wherein the first split ring has a capacitance and the second split ring has a capacitance, and a capacitance between the first split ring and the second split ring are connected in parallel. 
     
     
         10 . The device according to  claim 1 , wherein the first split ring has an inductance and the second split ring has an inductance, and the inductance of the first split ring and the inductance of the second split ring are serially connected to each other. 
     
     
         11 . The device according to  claim 1 , wherein the first split ring has a “C” shape. 
     
     
         12 . A communication apparatus comprising:
 an antenna device comprising:
 a first split ring comprising a conductor and having an opening and a first gap; 
 a second split ring comprising a conductor, formed in the opening of the first split ring, and having a second gap at a position facing the conductor of the first split ring; and 
 a power supply line connected to the first split ring; and 
   a processor that transmits and receives data to and from an external apparatus through the antenna device.   
     
     
         13 . The communication apparatus according to  claim 12 , further comprising:
 a dielectric plate, wherein   the first split ring and the second split ring are positioned on the dielectric plate.   
     
     
         14 . The communication apparatus according to  claim 13 , wherein
 the first split ring is positioned on a first surface of the dielectric plate, and   the second split ring is positioned on a second surface facing the first surface.   
     
     
         15 . The communication apparatus according to  claim 12 , wherein
 the second gap is in a direction opposite to a direction of the first gap.   
     
     
         16 . The communication apparatus according to  claim 12 , wherein the first split ring has a capacitance and the second split ring has a capacitance, and a capacitance between the first split ring and the second split ring are connected in parallel. 
     
     
         17 . The communication apparatus according to  claim 12 , wherein the first split ring has an inductance and the second split ring has an inductance, and the inductance of the first split ring and the inductance of the second split ring are serially connected to each other. 
     
     
         18 . The communication apparatus according to  claim 12 , wherein the communication apparatus is a POS terminal. 
     
     
         19 . The communication apparatus according to  claim 12 , wherein the communication apparatus is a printer. 
     
     
         20 . The communication apparatus according to  claim 12 , wherein the communication apparatus is a scanner.